Internal-combustion engine.



Patented May 2, 1905.

` ArtNr trice.

LUDVIG MERTENS, OF CHARLOTIENBURG, GERMANY, ASSIGNOR TO ABBE ENGINEERING CO., OF NEIV YORK, N. Y.

INTERNAL-COMBUSTION ENGINE.

SPECIFICATION forming part of Letters Patent NQ. 789,047, dated May 2, 1905.

Application iled October 29, 1903. Serial No. 179,007.

To all 11171/0777/ it 711mg/ concern:

Be it known that I, LUDWIG MERTENS, a citi- Zen of the Empire of Germany, residing in Charlottenburg, in said Empire of Germany, haveinvented certain new and usefu'l Improvements in Internal- Combustion Engines, of which the following` is a specification.

This invention relates to improvements in two-cycle internal-combustion engines with two or more single acting cylinders and charged by aseparate single-acting Jfeed-pump with explosive mixture without compressing the same; and the objects ot' the improved engine are, lirst, to arrange in connection with one or more single-acting combustion-cylinders a feed-pump for supplyingthe explosive gas and air mixture at each stroke of the feedpuinp to the combustion-cylinders; secondly, to extend the connecting-rod of the piston of the feed-pump beyond the pump crank-shaft and providing the same with a counterweight vfor equalizing the speed of the moving masses, and, thirdly, to provide the feed-pump with a butter device for regulating the speed of the moving masses.

For these purposes the invention consists, primarily, of the connection with one or more single-acting combustion-cylinders provided with an admission-valve at one end, of a separate feed-pump provided with means for admitting the explosive gas and air mixture,

means for connecting' the feed-pump with the admission end ot' each combustion-cylinder, means for igniting the explosive gas and air mixture in said combustion-cylinders, and means for conducting ol' the products of combustion through the exhaust-openings at the middle oi' the combustion-cylinder; and the invention consists, further, in providing the connecting-rod of the pump-piston with a counterweight for neutralizing the shocks of the moving masses and of a bu lier device arranged in connection with the feed-pump; and the invention consists, lastly, of certain additional details ot' construction, which will be full y described hereinafter and linally pointed out in the claims.

In the accompanying drawings, Figure 1 represents on thcleft-hand side a vertical longitudinal section of a vertical internal-combustion engine with two single-acting cylinders, taken on line A B, and on the right of the figure an elevation of the same; and Fig. 2 is a vertical transverse section on line O I), Fig. 1.

Similar figures of reference indicate corresponding parts.

The internal-combustion engine shown in Figs. 1 and 2 comprises two single-acting cylinders 1 and 2 and one single --acting feedpump 3. The two cylinders are jacketed and mounted on a hollow cast-iron head-plate 32, which is supported by eight pillars 33, secured in the base-plate 34. The cylinders 1 and 2 are each provided with a plurality of outlets 20 at about thc middle of their length and with an inlet 35 for an ignition. device of any known construction. (Not shown.) The pistons 17 and 18 are connected by suitable connecting-rods with the cranks 19 19 of the crankeshat't 5, said cranks being arranged at an angle of onehundred and eighty degrees to each other. The outlets 2O in each cylinder are made long enough so that they are opened by the respective pistons 17 and 18 during the rotation of the corresponding crank 19 through an angle of about ninety degrees. In the head-plate 32 is formed a cavity or chamber for collecting the escaping gases ot' combustion, which are conducted oi'f through the outlet 36 and a pipe connected therewith. The cooling-water is conducted through the jackets ot' the two cylinders 1 and 2 in thedirection otl the arrows 38, 39, and 37.

For the admission otl the explosive gas and air mixture spring-pressed valves 14 15 are arranged within the jacketed valve-chambers 40 41 on the tops of the two cylinders. The jacket ot' each valve-chamber is divided by a horizontal partition 42 into two parts communicating' with the valve-chamber proper by several apertures 43 44. The lower jacketed portions of the two valve-chambers 4041 communicate with a chamber 45 beneath the air-inlet valve 10, to which latter the fresh air is conducted through a tube 46. The airinlet valve 10 is normally held in its closed position by a helical spring 50. rIhe upper jacketed portions of the valveschambers 40 and 41 communicate, by branches 47 47, the bifurcated and bent tube 48, and the tube 11, with the cylinder 3 of the feed-pump. This cylinder 3 is secured in the head-plate 32, and its top cover is provided with a spring-pressed gas-inlet valve 9. The lower cover of the cylinder 3 is provided with several holes 105 for giving access to the outer air. The gas is conducted from any suitable source of supply through the pipe 8 to the casing of the valve 9. The gas-inlet valve 9 and the air-inlet valve 10 are simultaneously opened and closed by a cam 12 on the shaft 49 by means of a roller and a two-armed lever 13. The shaft 49 is driven from the crank-shaft 5 at the same rate of speed by means of any known transmission. (N ot shown.) To the shaft 49 are applied two additional cams for actuating the two admission-valves 14 15 alternately by means of two bell-crank levers 16, having' antifrictionrollers at their ends. The piston 51 of the feed-pump is driven from a second crank-shaft 4 by means of a connecting-rod 26, the cross-head 30, and the piston-rod 52. The second crank-shaft 4 is driven from the main crank-'shaft 5, by means of gear-wheels 6 and 7, at such a rate that the former makes doublethe number of the rotations of the latter. The feed-pump is thereby enabled to force a full charge of explosive mixture into either one of the two cylinders 1 2 alternately.

rl`he internalecombustion engine described is operated as follows: During the downward stroke the pump-piston 51 not only sucks in the air through the open air-inlet valve 10, the chamber 45, the lower jacketed portion of the same, the apertures 44 and 43, the upper jacketed portion, the branch tube 47, andthe tubes 48 11, but also gas from the supplytube 8 through the open gas-valve 9. During the upward stroke the piston 51 partly compresses the mixture of gas and air and forces it into either cylinder 1 or 2 through the tubes 11 48, the branch tube 47, and the open admission-valve 14.

The two gear-wheels 6 and 7 and the two crank-shafts4 and 5 are so disposed that when either piston (17 in Fig. 1) during its downward stroke commences to uncover the outlets 20 the pump-piston 51 occupies its lowest position and has completed the suction of the mixture. Then the burned gases will escape from the cylinder 1 through the uncovered outlets 20, the cavity in the head-plate 32, and

the outlet 36, while the piston 17 reaches its lowest position and the pump-piston 51 goes upward and arrives about the middle of its path. At this moment the admission-valve 14 is opened, when the pump-piston 51, having meanwhile partly compressed the explosive mixture, will force most of the latter into the cylinder 1. On the piston 17 ascending it will soon again cover the outlets 20, and at this moment the admission-valve 14 is again closed, when the pump-piston 51 will have reached its highest position. The admissionvalve 14 being now closed, the explosive mix ture will be compressed during the remaining part of the upward stroke of the piston 17. rlhe pump-piston 51 goes downward and sucks in a fresh charge of explosive mixture. On the piston 17 attaining its highest position the explosive mixture is ignited in the usual well-known manner, when the explosion will take place and throw the piston 17 downward. 1n the other cylinder, 2, similar occurrences take place.

It will be evident that during the upward or downward stroke of the pump-piston the moving masses of the pump will exercise an unfavorable influence upon the teeth of the gear-wheels 6 7, for the reason that during the first and the third quarter of each rotation of the pump crank-shaft 4 these masses are accelerated, while during the second and the fourth quarter of each rotation they are retarded. This means that the teeth of the gear-wheels 6 7 are subjected to more or less violent shocks corresponding to the speed of the motor, so that they are liable to fractures. To remedy this defect, the connecting-rod 26 islengthened and beyond the crank-pin 27 and provided with a counterweight 53 of such a size that the center of gravity of the whole connectingrod 26 is located at a certain point beneath the crank-pin 27 and that its weight in respect to the crank-pin will be about like that of the reciprocating masses of the pump.

During the swinging motionof the connecting-rod 26 around the cross-head pin 28 and the crank-pin 27, respectively, the mass of this rod 26 will then be accelerated during the second and fourth quarters of the rotation of the pump crank-shaft 4 and retarded during the first and third quarters, while the tangential components of the forces thereby produced on the crank-pin 27 will be about alike in size, but opposed in direction to the tangential components of the forces produced by the reciprocating masses of the pump. The tangential component of the resultant of all these forces of the masses of the pump will be but very small, and up to a certain speed of the motor it will always be smaller than the useful resistance to be overcome by the pump-crank. In the gearing 6 7, therefore, the objectionable shocks will be avoided, since the driving gear-wheel 6 will always have to overcome a certain resistance. In high-speed engines,however,where the mean speed of the pump-piston amounts to four, five, and more meters per second, the resultant of all the forces will become so great that the teeth of the gear-Wheels 6 7 will again be subjected to dangerous shocks. In order to remedy this defect, the total weight of the connectingrod 26, ascertained in the manner indicated above, is reduced by about ten to twenty In this case the tangential comper cent.

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ponent of the forces of the masses will be very small during the second and third quarters of the rotation of the pump-crank and a little larger than in the case before mentioned during the fourth and lirst quarters of rotation. This excess is annihilated by the buifer device illustrated in Fig. 2.

The guide 29 for the cross-head 30 is made in the nature of a dash-pot and the crosshead 30 as a butter-piston reciprocating therein. The dash-pot 29 is provided with a plurality of apertures 31, located on a certain point ot' the stroke of the piston 30, which is to be ascertained by calculation or by experiments. When the cross-head 30 has covered during its upward stroke the apertures 31,` it will commence to compress the air contained in the dash-pot 29 when the tangential component ot' the force produced by the compressed air on the crank-pin 27 will be about alike and opposed to the tangential component of the resultant of the forces of the masses. The same is the case when the compressed air is allowed to expand during the first quarter of the rotation of the pumpcrank. Thus the injurious influence of the vforces of the masses upon the gearing can be neutralized for the highest speeds of the motor.

rl`he number of the combustion-cylinders of the motor may be increased, but the ratio of the gearing 6 7 has then to be altered accordingly. For example, when the motor is made to comprise three single-acting explosioncylinders the ratio of the gear-wheels 6 and 7 must be three to one-thatis to say, the pump crank-shaft must make three rotations for every rotation of the motor crank-shaft.

Having thus described my invention, l claim as new and desire to secure by Letters Patentl. In a two-cycle internal-combustion engine, the combination, with aplurality of combustion-cylinders, each provided with a plurality of outlets, of a power-piston in each cylinder, a single-acting feed-pump, a pumppiston reciprocating in the cylinder of said feed-pump, means for admitting an explosive gas and air mixture to the cylinder of said feed-pump, means for conducting the explosive mixture alternately from the feed-pump to each of said combustion-cylinders, and a buffer device for the piston of the feed-pump.

2. In a two-cycle internal-combustion engine, the combination, with a plurality of combustion-cylinders, each provided with a plurality ot' outlets, of a power-piston in each cylinder, a single-acting feed-pump, a pumppiston reciprocating in the cylinder of said feed-pump, means for admitting an explosive gas and air mixture to said feed-pump, means for conducting the explosive mixture alternately to each of said combustion-cylinders, a dash-pot connected with said feed-pump and provided at or near its middle with a plurality of openings, and a buer-piston reciprocated in said dash-pot and connected with said pumppiston.

8. In a two-cycle internal-combustion engine` the combination, with a plurality of combustion-cylinders, each provided with a plurality of outlets, of a power-piston in each cylinder, a single-acting feed-pump, a pumppiston reciprocating in the cylinder ot' said feed-pump, means for admitting an explosive gas and air mixture to said feed-pump, means for conducting the explosive mixture alternately to each' of said combustion-cylinders, a motor crank-shaft, connecting-rods between the power-pistons and the motor crank-shaft, a pump crank-shaft, a connecting-rod between the pump-piston and the pump crank-shaft, a buffer device for the piston of the feed-pump, and a gear-wheel transmission between the motor crank-shaft and the pump crank-shaft, the proportionof said gear-wheels being such that the feed-pump forces a charge of explosive mixture at every stroke of its piston alternately into each of said combustion-cylinders.

4. In a two-cycle internal-combustion engine, the combination, with a plurality of combustion-cylinders, each provided with a plurality of outlets, of a power-piston in each cylinder, a single-acting feed-pump, a pumppiston reciprocating in the cylinder of said feed-pump, means for admitting an explosive gas and air mixture to said feed-pump, means for conducting the explosive mixture alternately to each of said combustion-cylinders, a motor crank-shaft, connecting-rods between the power-pistons and the motor crank-shaft, a pump crank-shaft, a connecting-rod between the pump-piston and the pump crank-shaft, said connecting-rod being extended beyond the crank of said crank-shaft and provided with a counterweight so that its center of gravity is beyond the crank-pin, and a gearwheel transmission between the motor crankshaft and the pump crank-shaft.

In testimony whereof l have signed my name to this specification in the presence of two subscribing witnesses.

LUDWIG MERTENS.

Witnesses WOLDEMAR HAUPT, HENRY HAsPER. 

